Attitude Independent Magnetometer Calibration Considering Magnetic Torquer Coupling Effect

摘要

THREE-AXIS magnetometer (henceforth TAM) is widely usednas a component of spacecraft attitude sensors.During the launchnand on-orbit period, TAM is affected by mechanical distortion,nthermal gradients, and internal magnetic moment disturbance ofnmagnetic actuator. The typical purpose of calibration is to estimatenfactors that affect raw measurements in the magnetometer frame.nOver the past several years, many studies have been conductednpertaining to attitude-independent calibration [1–3].Generally, thesenstudies were focused on the computation of calibration parametersnwithout including magnetic torquer (MTQ) coupling effect. How-never, as an example, TAM measurement was found to be contami-nnated by MTQ activation according to the first Korea MultipurposenSatellite (KOMPSAT-1) flight data. If the several preceding methodsntake KOMPSAT-1 TAM data, the outcome could be an incorrectncalibration. In this study, the proposed calibration method cannestimate theMTQcoupling effect togetherwith bias, scale factor, andnnonorthogonality terms. The particle swarm optimization (PSO)nalgorithm is used to estimate 18 calibration parameters. The PSOnalgorithm is known to be a powerful algorithm that searches for ansolution tominimize nonlinear cost functions with a simple structurenfor computer implementation